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Constantino PB, Dionísio TJ, Duchatsch F, Herrera NA, Duarte JO, Santos CF, Crestani CC, Amaral SL. Exercise attenuates dexamethasone-induced hypertension through an improvement of baroreflex activity independently of the renin-angiotensin system. Steroids 2017; 128:147-154. [PMID: 29054562 DOI: 10.1016/j.steroids.2017.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 11/19/2022]
Abstract
Dexamethasone-induced hypertension may be caused by baroreflex alterations or renin-angiotensin system (RAS) exacerbation. Aerobic training has been recommended for hypertension treatment, but the mechanisms responsible for reduction of arterial pressure (AP) in dexamethasone (DEX) treated rats are still inconclusive.This study evaluated whether mechanisms responsible for training-induced attenuation of hypertension involve changes in autonomic nervous system and in RAS components. Rats underwent aerobic training protocol on treadmill or were kept sedentary for 8 weeks. Additionally, animals were treated with DEX during the last 10 days of exercise. Body weight (BW), AP and baroreflex activity were analyzed. Tibialis anterior (TA), soleus (SOL) and left ventricle (LV) were collected for evaluation of RAS components gene expression and protein levels. Dexamethasone decreased BW (20%), caused TA atrophy (16%) and increased systolic AP (SAP, 16%) as well as decreased baroreflex activity. Training attenuated SAP increase and improved baroreflex activity, although it did not prevent DEX-induced BW reduction and muscle atrophy. Neither DEX nor training caused expressive changes in RAS components. In conclusion, exercise training was effective in attenuating hypertension induced by DEX and this response may be mediated by a better autonomic balance through an improvement of baroreflex activity rather than changes in RAS components.
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Affiliation(s)
- Paula B Constantino
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Department of Physical Education, Science Faculty, São Paulo State University (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru, SP, Brazil
| | - Thiago J Dionísio
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP 17012-901, Brazil
| | - Francine Duchatsch
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Department of Physical Education, Science Faculty, São Paulo State University (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru, SP, Brazil
| | - Naiara A Herrera
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Department of Physical Education, Science Faculty, São Paulo State University (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru, SP, Brazil
| | - Josiane O Duarte
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Rodovia Araraquara Jaú, km 01 - s/n, Campos Ville, Araraquara, SP 14800-903, Brazil
| | - Carlos F Santos
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP 17012-901, Brazil
| | - Carlos C Crestani
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Rodovia Araraquara Jaú, km 01 - s/n, Campos Ville, Araraquara, SP 14800-903, Brazil
| | - Sandra L Amaral
- Joint Graduate Program in Physiological Sciences, PIPGCF UFSCar/UNESP, Rodovia Washington Luiz, km 235, Monjolinho, 676, São Carlos, SP, Brazil; Department of Physical Education, Science Faculty, São Paulo State University (UNESP), Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru, SP, Brazil.
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Baptista MJ, Nogueira-Silva C, Areias JC, Correia-Pinto J. Perinatal profile of ventricular overload markers in congenital diaphragmatic hernia. J Pediatr Surg 2008; 43:627-33. [PMID: 18405707 DOI: 10.1016/j.jpedsurg.2007.08.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 08/03/2007] [Accepted: 08/11/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND In congenital diaphragmatic hernia (CDH), pulmonary hypertension increases right ventricle (RV) afterload, which could impair heart function and contribute to poor outcome for most affected infants. Nevertheless, the real significance of vascular pulmonary alterations in perinatal hemodynamics is largely unknown. It is defined that ventricular pressure overload induces increased myocardium gene expression of B-type natriuretic peptide (BNP) and components of the renin-angiotensinogen and endothelin (ET)-1 systems. Our aim was to evaluate perinatal myocardium expression of these genes associated with ventricular pressure overload in a nitrofen-induced CDH rat model. METHODS In the nitrofen-induced CDH rat model, fetuses from dated pregnant Sprague-Dawley rats at 15.5, 17.5, 19.5 and 21.5 days postcoitum as well as newborn pups were assigned to 3 experimental groups: control, nitrofen (exposed to nitrofen, without CDH), and CDH (exposed to nitrofen, with CDH). Myocardial samples collected from the RV and left ventricle (LV) were processed for quantification of messenger RNA (mRNA) of BNP, angiotensinogen, and ET-1. RESULTS The perinatal expression of BNP, angiotensinogen, and ET-1 mRNA in the RV and LV of the control group revealed daily changes. During gestation, the expression of BNP and angiotensinogen mRNA underwent significant oscillation compared with control in both nitrofen-exposed fetuses, although we cannot identify significant differences between the nitrofen and CDH groups. After birth, we found a significant increasing expression of all studied genes only in the RV of CDH pups. CONCLUSIONS Perinatal myocardial quantification of BNP, angiotensinogen, and ET-1 mRNA levels suggests that both nitrofen-exposed and control pups revealed prenatal variations of expression of the studied genes. Moreover, CDH is associated with significant molecular alterations only in the RV after birth.
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Affiliation(s)
- Maria João Baptista
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
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Correia-Pinto J, Baptista MJ, Pedrosa C, Estevão-Costa J, Flake AW, Leite-Moreira AF. Fetal heart development in the nitrofen-induced CDH rat model: the role of mechanical and nonmechanical factors. J Pediatr Surg 2003; 38:1444-51. [PMID: 14577066 DOI: 10.1016/s0022-3468(03)00494-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND/PURPOSE In congenital diaphragmatic hernia (CDH), it was recently shown that early and late gestational lung underdevelopment is caused by nonmechanical and mechanical factors, respectively. Heart underdevelopment, which might predict lung hypoplasia, is commonly attributed to mechanical factors. The authors analyzed whether nonmechanical and mechanical factors affect cardiac growth and correlations between lung and heart weights during gestation. METHODS Left-sided CDH was induced in pregnant Wistar rats by administration of nitrofen on E9.5. At selected gestational ages (E18, E20, and E22), the lungs and heart were harvested, weighed, and analyzed for DNA and protein contents. Left lung and heart weights were correlated at those gestational ages. Two experimental groups: nitrofen without CDH (nitrofen), and nitrofen with CDH (CDH), were compared with normal controls. RESULTS At E18, both nitrofen-exposed groups presented similar and significant left lung (LL) hypoplasia. As gestation progressed (E20 and E22), in the nitrofen group left lung (LL) hypoplasia decreased, whereas in the CDH group LL hypoplasia was exacerbated relative to normal controls. In contrast, at E18 and E20, heart-to-body weight ratios as well as cardiac DNA and protein contents were reduced significantly in all animals exposed to nitrofen, with no significant differences observed between nitrofen and CDH groups. As gestation progressed, the difference between cardiac parameters in nitrofen-exposed and normal control rats diminished, and at E22 no significant differences were documented. In the CDH group, significant correlations were seen between lung and heart weights at E18 (r = 0.65; P <.05) and E20 (r = 0.4; P <.05), whereas at term gestation (E22) no significant correlation was observed (r = 0.21, not significant). CONCLUSIONS Nonmechanical factors, which might be directed by nitrofen, play a role in the pathogenesis of lung and heart hypoplasia manifested precociously in fetal life, whereas mechanical compression might influence only lung growth during late gestation. Heart weight predicts lung weight only in early gestational ages.
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Affiliation(s)
- Jorge Correia-Pinto
- Department of Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
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